Creeper Oyster

Creeper Oyster a semi-rare drop dropped by Creepers. It can be used eaten (restores 1 hunger shank) but it's poisonous (deal 2 hearts of damage over few seconds). It's also used to make Diamond Ingots. As of version 4.89 they can be harvested from creepers by right clicking one with a pair of shears. Gathering them in this manner changes the color of a Creeper, letting the player know that that certain mob cannot be "snipped" again.